Heat Exchanger

ABSTRACT

A heat exchanger includes a plurality of heat exchanger units, each of which including header pipes ( 4,6 ) disposed in parallel to each other, a plurality of tubes ( 8 ) communicating with the header pipes and being disposed between the header pipes, fins ( 10 ) disposed between adjacent tubes, wherein a core portion ( 12 ) of the heat exchanger unit ( 2 ) is configured with the tubes and the fins layered therebetween; wherein the plurality of heat exchanger units are disposed in a direction that the tubes and the fins are arranged; and wherein the heat exchanger includes: fitting portions ( 16,18 ) which connect respective end portions ( 4   a,    6   a ) of the header pipes of the heat exchanger units that are adjacent to each other, and side plates ( 20,22,40,42,46,48 ) which connect opposing end portions ( 12   a ) of respective core portions of the heat exchanger units that are adjacent to each other.

TECHNICAL FIELD

The present invention is concerning a heat exchanger used as an exterior heat exchanger having both functions of condenser and evaporator for a heat pump system of a vehicle air conditioning.

BACKGROUND ART

Conventionally, the above referred heat exchanger comprises, for example, a pair of header pipes disposed with a space and in parallel to each other, a plurality of tubes communicating with both header pipes and being disposed parallel to each other with a small distance, and fins disposed between adjacent tubes. These tubes and fines that are layered constitute a core portion of the heat exchanger. In such a heat exchanger, a pair of header pipes are disposed to extend vertically, and a plurality of tubes are disposed to extend laterally, which is called as a lateral-coolant-flow type heat exchanger. In this type of heat exchanger, it is designed so that the length (vertical dimension) of the header pipes is larger than the length of tubes (lateral dimension).

However, in this lateral-coolant-flow type heat exchanger, there may often occur frost formation due to condensed water adhering to the surfaces of laterally disposed tubes, when the coolant is evaporated. If a layer of the frost grows up, there may be caused a deterioration of heat exchange efficiency.

Thus, as a heat exchanger which enables suppressing the frost formation or in other words facilitating condensed water to be discharged, a so-called vertical-coolant-flow type heat exchanger has been developed, in which a plurality of tubes are disposed to extend vertically.

In this vertical-coolant-flow type heat exchanger, compared with the lateral-coolant-flow type heat exchanger, it is designed so that the length (lateral dimension) of tubes is larger than the length (vertical dimension) of the header pipes, resulting in a significantly increased number of tubes.

In the above referred vertical-coolant-flow type heat exchanger, since the numbers of tubes and fins increase significantly, a higher dimension accuracy is required for each of a plurality of tubes and fins. In addition, the productivity of the heat exchanger may be lowered, because a strict processing accuracy is required for providing connecting holes with a predetermined intervals on the header pipes for connecting a plurality of tubes.

Thus, a lateral-coolant-flow type heat exchanger is disclosed (for example refer to the patent literature PTL 1), which comprises a plurality of the vertical-coolant-flow type heat exchanger units, which are ordered in the direction that tubes and fins of each heat exchanger unit are layered alternatingly. In this known heat exchanger, by being split into a plurality of heat exchanger units, there is no need to strictly control the dimensional accuracies of tubes and fins and the processing accuracy of the connecting holes of header pipes, thus resulting in an advantage of productivity increase of heat exchanger.

CITATION LIST Patent Literature

Patent Literature 1: Japanese patent No. 2898800

SUMMARY OF INVENTION Technical Problem

For an exterior heat exchanger of a heat pump system of vehicle air conditioning, it is required to have an enhanced rigidity of total structure of the heat exchanger, since it is arranged on the front of vehicle and thus suffers largely from vibration and bending moment during the driving of vehicle. The above mentioned conventional heat exchanger comprises side plates connecting the vertically adjacent heat exchanger units by combining the opposing end portions of core portions of respective units. However, because connection between the heat exchanger units is done only with a side plate, the heat exchanger as a whole does not entirely have a sufficient rigidity against bending.

Further, the above mentioned conventional heat exchanger is of a lateral-coolant-flow type heat exchanger. With a vertical-coolant-flow type heat exchanger, because the number of tubes increase significantly as explained above, a high dimensional accuracy and a strict processing accuracy are required. However, in the conventional heat exchanger, no particular care is employed, thus a problem of productivity increase of heat exchange is still remaining.

Further, in the above mentioned conventional heat exchanger, no measure is taken against deterioration of heat exchange efficiency, a degradation of external appearance and an adverse effect of downsizing due to unitization of the heat exchanger units, which may be caused by the heat exchanger assembled by connecting heat exchanger units.

The present invention is made based on above mentioned observation of the problem. The purpose of the present invention is to provide a heat exchanger in that the bending rigidity, productivity, and heat exchange efficiency are enhanced, and further enabling to make better the external appearance, leading to downsizing.

Solution to Problem

In order to realize the above mentioned purpose, the heat exchanger of the present invention comprises a plurality of heat exchanger units, each of which including header pipes disposed in parallel to each other, a plurality of tubes communicating with the header pipes and being disposed between the header pipes, fins disposed between adjacent tubes, wherein a core portion of the heat exchanger unit is configured with the tubes and the fins layered therebetween; wherein the plurality of heat exchanger units are disposed in a direction that the tubes and the fins are arranged; and wherein the heat exchanger comprises: fitting portions which connect respective end portions of the header pipes of the heat exchanger units that are adjacent to each other; and side plates which connect opposing end portions of respective core portions of the heat exchanger units that are adjacent to each other.

Preferably, the header pipes are therein disposed in parallel to each other on upper side and on lower side; the plurality of tubes, extending in vertical direction, are arranged between the header pipes and communicated with both of the header pipes; the fitting portion includes an upper-side fitting portion which engages opposing end portions of respective upper-side header pipes of the heat exchanger units that are adjacent to each other, and a lower-side fitting portion which engages opposing end portions of respective lower-side header pipes of the heat exchanger units that are adjacent to each other; and the side plate includes an inlet-side side plate on the inlet side of air blowing onto the core portion, which is provided to one of the opposing end portions of core portions of the heat exchanger units that are adjacent to each other, and an outlet-side side plate on the outlet side of air blowing onto the core portion, which is provided to other one of the opposing end portions of core portions of the heat exchanger units that are adjacent to each other.

Preferably, the side plate includes a connecting portion formed along longitudinal direction of the tubes and fins, of which both end portions in the longitudinal direction being connected respectively to the header pipes, and a joining portion extending and being bent from the connecting portion, which is joined to a opposing side plate of adjacent core portion.

Preferably, the side plate has a cross section of L-letter shape.

Preferably, the connecting portion or the joining portion is bent towards the connecting portion or the joining portion of the opposing side plate, and thus the side plate has a cross section of U-letter shape.

Preferably, the side plates are joined to each other so that a space enclosed with core portions that are adjacent to each other and with fitting portions thereof that are opposing to each other is blocked.

Preferably, the sideplate includes a bolt insertion hole on the joining portion, by which the side plates that are opposing to each other are joined with a bolt inserted therein; and the bolt insertion hole is provided on the side plates that are opposing to each other, which are arranged on a position that these side plates are not in contact to each other and can block the space in a direction of blowing air onto the core portion.

Preferably, the bolt insertion hole has a diameter larger than a diameter of the bolt.

Preferably, the side plates are provided as identical parts, and are arranged symmetrically to each other at the end portions of core portions that are adjacent to each other, and are arranged in front-back direction to each other along the direction of blowing air onto the core portion.

Advantageous Effects of Invention

According to the present invention, since the heat exchanger units that are adjacent to each other can be firmly connected with the fitting portions that connect the end portions of respective header pipes and with the side plates that connect the end portions of the opposing core portions of the respective heat exchanger units, the bending rigidity of the whole heat exchanger can be enhanced.

Further, according to the present invention, since the side plates are joined to each other so that the space enclosed with the adjacent core portions and the fitting portions is blocked, by which an air escaping route between cores of the heat exchanger is blocked, allowing the whole amount of air blown at the heat exchanger to enter the core portions. Thus the heat exchange between air and coolant is facilitated, allowing the heat exchange efficiency of the heat exchanger to be enhanced.

Further, according to the present invention, since the bolt insertion hole is provided on the opposing side plates which are arranged on the positions that both these side plates are not in contact to each other and can block the space in the direction of blowing air onto the core portion, the bolt insertion hole can absorb the errors in dimension and assembly at the side plates, allowing to easily achieve unitization of the heat exchanger, so that a connection between the adjacent core portions can be performed without being shifted to each other in the direction of blowing air onto the core portion, leading to improvement of the external appearance and to enhance downsizing of the heat exchanger.

Further, according to the present invention, the bolt insertion holes is provided with a diameter larger than the diameter of the bolt, through which the errors in dimension and assembly of the heat exchanger are absorbed at the bolt insertion hole, allowing to easily control the errors in dimension and assembly, leading to enhancement of the productivity of the heat exchanger.

In addition, according to the present invention, by employing identical side plates which are provided symmetrically to each other at the opposing end portions of adjacent core portions and are arranged in front-back direction to each other along the air blowing direction to the core portions, it allows easily to produce and control the component parts of the heat exchanger, leading further to enhance the productivity of heat exchanger.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of the heat exchanger of an embodiment according to the present invention.

FIG. 2 is an enlarged perspective view of a connecting portion of the heat exchanger units of the heat exchanger shown in FIG. 1.

FIG. 3 is a perspective view of the right-hand side heat exchanger unit, seen from a different angle.

FIG. 4 is a front view of the side plate shown in FIG. 1.

FIG. 5 is a cross-sectional view of the connecting portion of the side plates shown in FIG. 1, seen from bottom side.

FIG. 6 is a cross-sectional view of the side plates of a variant embodiment of the present invention seen from bottom side.

FIG. 7 is a cross-sectional view of the side plates of an another variant embodiment of the present invention seen from bottom side.

DESCRIPTION OF EMBODIMENTS

In the following, it will be explained about the embodiments of the present invention referring to the associated figures.

FIG. 1 is a front view of the heat exchanger 1 of an embodiment according to the present invention. The heat exchanger 1 is of a vertical-coolant-flow type, and is configured with two heat exchanger units 2 being arranged in parallel in the lateral direction.

The heat exchanger unit 2 comprises upper- and lower header pipes 4, 6 disposed in parallel to each other extending in lateral direction, a plurality of tubes communicating with both header pipes 4,6 and being disposed parallel to each other with a small distance in between the header pipes 4,6, and fins 10 disposed between adjacent tubes 8. These tubes 8 and fines 10 that are layered constitute a core portion of the heat exchanger. The plurality of tubes 8 are connected by blazing at the connecting holes that are provided in regular intervals on the header pipes 4,6.

FIG. 2 shows an enlarged perspective view of a connecting portion of the heat exchanger units. In this embodiment, the lengths of the header pipes 4,6 of the heat exchanger unit 2 are designed to have approximately same lengths with those of the tubes 8. The two in parallel disposed heat exchanger units 2 are connected by fitting to each other the opposing end portions 4 a of the respective upper header pipes 4 of the adjacent heat exchanger units 2, forming the upper fitting portion 16, and by fitting to each other the opposing end portions 6 a of the respective lower header pipes 6 of the adjacent heat exchanger units 2, forming the lower fitting portion 16.

Further, the heat exchanger units 2 according to this embodiment are connected with an inlet-side side plate 20 and an outlet-side side plate 22, connecting the opposing end portions 12 a of the respective core portions 12 of the adjacent heat exchanger units 2. As shown in FIG. 1, assuming that air is blown from the front side in the figure to the rear side, the inlet-side side plate 20 is provided at the end portion 12 a of the right-hand-side core portion 12, and blocks the space 24 enclosed by the adjacent core portions 12 and by the upper- and lower fitting portions 16,18, at the air inlet side. And the outlet-side side plate 22 is provided at the end portion 12 a of the left-hand-side core portion 12, and blocks the space 24 at the air outlet side.

FIG. 3 shows a perspective view of the right-hand-side heat exchanger unit seen from a different angle. The respective end portions 4 a and 6 a of the upper- and lower header pipes in the right-hand-side heat exchanger unit of the laterally in parallel arranged heat exchanger units are provided as enlarged pipe ends 4A and 6A. The respective enlarged pipe ends 4A,6A of the right-hand-side header pipes 4,6 and the respective pipe ends 4 a, 6 a of the upper- and lower header pipes of the left-hand side heat exchanger unit are fitted to each other, forming the upper fitting portion 16 and the lower fitting portion 18.

Thereby the respective inner sides of the enlarged pipe ends 4A, 6A of the right-hand-side header pipes 4,6 and the respective outer sides of the pipe ends 4 a, 6 a of the left-hand-side header pipes being fitted to the enlarged pipe ends 4A, 6A are joined by blazing.

Further, the inlet-side side plate 20 and the outlet-side side plate 22 are joined by blazing respectively to the tube connection holes 14 and to a plate connection hole 26 that is provided with a same interval as those of the tube connection holes. Fins 10 are provided between provided respectively between the inlet-side side plate 20, out-let side side plate 22 and the their adjacent tubes 8. It should noted that the reference numeral 28 stands for the covers pressing the fins 10 positioned at the left- and right end portions of the heat exchanger 1.

FIG. 4 shows a front view of the inlet-side side plate, and FIG. 5 shows a cross-sectional view of the connecting portion of the inlet-side side plate 20 and the outlet-side side plates 22 seen from bottom side of FIG. 1. The inlet-side side plate 20 and the outlet-side side plate 22 according to this embodiment have a cross section of L-letter shape, and are identical parts having a same structure comprising a connecting portion 32 and a joining portion 30 extending and being bent from the connecting portion 32. The side plates 20,22 are joined to each other to block substantially the whole area of the space 24, by arranging symmetrically to each other at the opposing end portions 12 a of adjacent core portions in front-back direction along the air blowing direction to the core portions 12.

The connecting portion 32 are formed along the longitudinal direction of tubes 8 and fins 10, and the both end portions 32 a of the connecting portion 32 are inserted into a plate connection hole 26 formed on the upper- and lower header pipes 4,6 and connected thereby blazing.

Further, as shown in FIG. 5, the joining portion 30 is joined to the other joining portion 30 of the opposing side plate 20 (or 22) of the adjacent core portion 12. In the joining portion 30, a bolt insertion hole is provided, by which it is enabled to join the opposing inlet-side side plate 20 and the outlet-side side plate 22 by use of a bolt 34 inserted thereto. The bolt insertion hole 36 is a circular hole having a diameter larger than the diameter of the thread portion of the bolt 34, and is provided on the opposing inlet-side side plate 20 and outlet-side side plate 20 which are arranged on the positions that both these side plates are not in contact to each other and can block the space 24 in the direction of air blowing onto the core portion. By fastening with a bolt 34 inserted into the bolt insertion hole 36 and a nut 38, the opposing inlet-side side plate 20 and outlet-side side plate 22 can be joined together without unevenness in the mutual joining direction, absorbing the errors of dimension and assembly at the side plates.

As explained above, the heat exchanger 1 according to this embodiment can enhance the bending rigidity of the whole heat exchanger 1, since the heat exchanger units 2 that are adjacent to each other are firmly joined with the upper-side connecting portion 16 and lower-side connecting portion 18 and with the inlet-side side plate 20 and outlet-side side plate 22.

Further, since the inlet-side side plate 20 and outlet-side side plate 22 are joined to each other so that the space enclosed with the adjacent core portions 12 and the upper-side fitting portion 16 and lower-side fitting portion 18 is blocked, by which a air escaping route between cores of the heat exchanger is blocked, allowing the whole amount of air blown at the heat exchanger to enter the core portions 12. Thus heat exchanging between air and coolant is facilitated, allowing the heat exchange efficiency of the heat exchanger 1 to be enhanced.

Further, since the bolt insertion hole is provided on the opposing upper-side side plate 20 and lower-side side plate 22 which are arranged on the positions that both these side plates are not in contact to each other and can block the space 24 in the direction of blowing air onto the core portion 12, the connection between the core portions 12 that are adjacent to each other can be performed without being shifted to each other in the direction of blowing air onto the core portion 12, so that a bolt insertion hole 36 can absorb the errors in dimension and assembly at the inlet-side side plate 20 and outlet-side side plate 22, allowing to easily achieve unitization of the heat exchanger 1, leading to improvement of the external appearance and to enhance downsizing of the heat exchanger 1.

Further, the bolt insertion holes 36 are provided with a diameter larger than the diameter of the bolt 34, through which the errors in dimension and assembly of the heat exchanger 1 are absorbed at the bolt insertion hole 36, allowing to easily control the errors in dimension and assembly, leading to enhancement of the productivity of the heat exchanger 1.

In addition, by employing identical side plates for the inlet-side side plate 20 and outlet-side side plate 22 which are provided as identical parts and arranged symmetrically to each other at the opposing end portions 12 a of adjacent core portions 12 and in front-back direction to each other along the direction of blowing air onto the core portion 12, it allows easily to produce and control the component parts of the heat exchanger 1, leading further to enhance the productivity of heat exchanger 1.

The present invention is not limited to above described embodiments, and allows various modifications.

As just an example, in the above explained embodiment, the inlet-side side plate and outlet-side side plate are formed with a cross section having a L-letter shape. However, the present invention is not limited to this shape, if the bolt insertion hole is provided on the opposing upper-side side plate 20 and lower-side side plate 22 which are arranged on the positions that both these side plates are not in contact to each other and can block the space 24 in the direction of blowing air onto the core portion 12.

More particularly, as shown in FIG. 6, a bending portion 44 which is bent in the direction that the joining portions 30 are opposing to each other may be provided to the inlet-side side plate 40 and to the outlet-side side plate 42 so that these side plates are provided as identical parts having a cross section of U-letter shape and are arranged symmetrically to each other and in front-back direction to each other along the direction of blowing air onto the core portion 12.

Further, as shown in FIG. 7, a bending portion 50 which is bent in the direction that the connection portions 32 are opposing to each other may be provided to the inlet-side side plate 46 and to the outlet-side side plate 48 so that these side plates 46,48 are provided as identical parts having a cross section of U-letter shape and are arranged symmetrically to each other and in front-back direction to each other along the direction of blowing air onto the core portion 12.

Also with the embodiments shown in FIGS. 6,7, similar to the above explained embodiments, while the errors in dimension and assembly are absorbed at the opposing side plates, it allows to enhance unitization of the exchanger 1 and to improve external appearance and down-sizing of the heat exchanger 1, leading to higher productivity of the heat exchanger 1.

Moreover, as these side plates are formed with a cross section of U-letter shape, the rigidity of the side plates are enhanced and their durability is also improved, compared with those with a cross section of L-letter shape.

Further, though, in the above explained embodiments, the bolt insertion hole 36 is provided as a circular hole, this hole may be an elongate hole if it has a longer diameter than the diameter of the bolt 34. With such an elongate hole, the errors in dimension and assembly of the heat exchanger 1 can effectively absorbed at the bolt insertion hole 36.

Further, though, in the above explained embodiments, the heat exchanger 1 is described with an arrangement of two heat exchanger units 2 disposed in parallel in lateral direction, the present invention is not limited to this arrangement. An arrangement of three or more heat exchanger units may also be employed.

Reference Signs List

1 Heat exchanger

2 Heat exchanger unit

4 Header pipe (upper-side header pipe)

4 a End portion

6 Header pipe (lower-side header pipe)

6 a End portion

8 Tube

10 Fin

12 Core portion

12 a End portion

16 Fitting portion (upper-side fitting portion)

18 Fitting portion (lower-side fitting portion)

20, 40, 46 Side plate (inlet-side side plate)

22, 42, 48 Side plate (outlet-side side plate)

24 Space

30 Joining portion

32 Connecting portion

32 a End portions

34 Bolt

36 Bolt insertion hole 

1. A heat exchanger, comprising: a plurality of heat exchanger units, each of which including header pipes disposed in parallel to each other, a plurality of tubes communicating with the header pipes and being disposed between the header pipes, fins disposed between adjacent tubes, wherein a core portion of the heat exchanger unit is configured with the tubes and the fins layered therebetween; wherein the plurality of heat exchanger units are disposed in a direction that the tubes and the fins are arranged; and wherein the heat exchanger comprises: fitting portions which connect respective end portions of the header pipes of the heat exchanger units that are adjacent to each other; and side plates which connect opposing end portions of respective core portions of the heat exchanger units that are adjacent to each other.
 2. The heat exchanger according to claim 1, wherein the plurality of heat exchanger units are arranged laterally; the header pipes are therein disposed in parallel to each other on upper side and on lower side; the plurality of tubes, extending in vertical direction, are arranged between the header pipes and communicated with both of the header pipes; the fitting portion includes an upper-side fitting portion which engages opposing end portions of respective upper-side header pipes of the heat exchanger units that are adjacent to each other, and a lower-side fitting portion which engages opposing end portions of respective lower-side header pipes of the heat exchanger units that are adjacent to each other; and the side plate includes an inlet-side side plate on the inlet side of air blowing onto the core portion, which is provided to one of the opposing end portions of core portions of the heat exchanger units that are adjacent to each other, and an outlet-side side plate on the outlet side of air blowing onto the core portion, which is provided to other one of the opposing end portions of core portions of the heat exchanger units that are adjacent to each other.
 3. The heat exchanger according to claim 1, wherein the side plate includes a connecting portion formed along longitudinal direction of the tubes and fins, of which both end portions in the longitudinal direction being connected respectively to the header pipes, and a joining portion extending and being bent from the connecting portion, which is joined to a opposing side plate of adjacent core portion.
 4. The heat exchanger according to claim 3, wherein the side plate has a cross section of L-letter shape.
 5. The heat exchanger according to claim 3, wherein the connecting portion or the joining portion is bent towards the connecting portion or the joining portion of the opposing side plate, and thus the side plate has a cross section of U-letter shape.
 6. The heat exchanger according to claim 4, wherein the side plates are joined to each other so that a space enclosed with core portions that are adjacent to each other and with fitting portions thereof that are opposing to each other is blocked.
 7. The heat exchanger according to claim 6, wherein: the side plate includes a bolt insertion hole on the joining portion, by which the side plates that are opposing to each other are joined with a bolt inserted therein; and the bolt insertion hole is provided on the side plates that are opposing to each other, which are arranged on a position that these side plates are not in contact to each other and can block the space in a direction of blowing air onto the core portion.
 8. The heat exchanger according to claim 7, wherein the bolt insertion hole has a diameter larger than a diameter of the bolt.
 9. The heat exchanger according to claim 8, wherein the side plates are provided as identical parts, and are arranged symmetrically to each other at the end portions of core portions that are adjacent to each other, and are arranged in front-back direction to each other along the direction of blowing air onto the core portion. 